CWmike writes "Gregg Keizer reports that Adobe's Reader X stymied a recent attack campaign, researchers said Thursday. But they're not sure why. 'I don't want to take anything away from Adobe — after all, a win is a win — but this particular exploit appears to be designed with previous versions of Reader in mind,' said Chris Greamo, who heads the security research lab at Invincea. 'What appears to have happened is that the exploit breaks, but we don't have a good sense if the sandbox was able to contain it.' Reader X, an upgrade issued last year, features a 'sandbox' designed to protect users from PDF exploits. Adobe claimed that a recently-addressed bug in Chrome that lets attackers escape the browser's sandbox was not present in Reader X's sandbox code. Google patched that bug, the first to earn the company's top bug bounty of $3,133, three weeks ago. Adobe said Thursday it will would ship its next regular update for Reader on Tuesday, Feb. 8."